Manufacture of glassware



I (No Model.)

0. ULFIG. MANUFACTURE OF GLASSWARE.

Patented 1160.29, 1891.

UNITED STATES PATENT OFFICE.

CHARLES ULFIG, OF MARTINS FERRY, OHIO.

MANUFACTURE OF GLASSWARE.

SPECIFICATION forming part of Letters Patent No. 466,062, dated December 29, 1891.

Application filed September 1, 1890. Serial No. 363,625- (No model.)

T0 at whom, it may concern.-

Be it known that I, CHARLES ULFIG, of Martins Ferry, in the county of Belmont and State of Ohio, have invented a new and useful Improvement in the Manufacture of Glassware, of which the following is a full, clear, and eX- act description.

The object of my invention is to provide means for forming screw-threaded sockets in articles of glassware.

The invention is of general application; but I have devised it primarily for the purpose of forming threaded sockets in the bowls of central-draft lamps for the purpose of connecting the central draft-tubes thereto, and shall so describe it.

The invention is illustrated in the accompanying drawings, in which-- Figure 1 is a vertical sectional view of a lamp bowl and tube,the screw-thread for con nection of which is made according to my invention. Fig. 2 is a vertical sectional view illustrating the application of the construction shown in Fig. 1 to a lamp having a foot or stem. Fig. 3 is a vertical sectional View illustrating the mode of manufacture of the lamp shown in Figs. 1 and 2.

Like symbols of reference indicate likev parts in each.

In the drawings, Fig. 1, 2 represents the glass bowl or oil-fount of the lamp, and 3 is the metal central draft-tube. The tube has at the base or is soldered or otherwise secured to a sheet-metal collar4, formed with a peripheral screw-thread and preferably having a flange 5 at its lower end. The lamp-bowl has at its base an inwardly-projecting socket 6, which is open at the top to accommodate the draft tube and is internally screwthreaded. To attach the draft-tube to the bowl, the tube is inserted into the bowl through the socket and the collar t is screwed into the latter until the flange 5' engages and presses against the bowl. To seal the joint between the tube and bowl and to lock them inseparably together, I place insoluble glass and metal bindingcement between the collar 4 and the socket before screwing them together. To regulate the draft of air through the tube Imayemploya perforated cap 7, having slit sides, which make it laterally compressible and resilient. The cap is inserted into the tube, as shown in Fig. 1, and by adjusting it vertically therein, so as to vary the extent of projection of the perforated sides, the area of air-opening may be varied to suit the requirements of the particular style of lamp-burner and the size of the flame.

In Fig. 2 I show the lamp bowl and tube of Fig. 1 fitted with a hollow stem or foot 9. The upper end of this stem is externally threaded, and is screwed into the collar 4 within the socket 6. WVhen the tube is attached to the lamp by any of these modes, the union is very secure and strong, all leakage of the oil is prevented, and a desirable and merchantable article is afforded.

I shall now proceed to describe how I manufacture the lamp-bowls in proper form to receive the central draft-tubes, referring in such description to Fig. 3. It is in this mode of manufacture that my invention consists.

To make the lamp-bowl of the form shown in Fig. 1, I use a glass blow-mold 10, Fig. 3, having a base 11 with a central hole adapted to receive a peg 12, the head of which. projects into the mold-cavity and'at its end is formed with depressions b, as shown. Before blowing the glass a spirally-corrugated annular thin sheet-metal ferrule 13 is placed around the top of the peg, and the latter is inserted into the mold, as shown in Fig. 3. The glass is then blown into the mold and shapes itself around the ferrule, so as to take the impression of the thread and to form the socket 6, while the glass at the top of the peg blows down into the depressions b, so as to form a thin overblow c. IVhen the bowl has been blown, it is taken from the mold and peg, and without removing the ferrule it is passed through the annealing-lean When the bowl is taken from the lear, the ferrule is removed by means of a wrench, which may be fitted to slots at inthe ferrule, and the overblow removed by tapping upon it. This forms a very convenient and accurate means for forming the screw-thread on the fount. An especial advantage incident to this use of the ferrule is this: When it is attempted to form a screwthreaded socket in glass by shaping the glass around a solid threaded plug, it is found that because of the bulk of such plug it does not become heated quickly by contact with the hot glass, and therefore in cooling shrinks less than does the glass, thereby making the glass very apt to break. \Vhen the glass is formed around the ferrule, the thin substance of thelatterbecomes heated quickly to nearly the same temperature as the glass, and when the glass cools the ferrule shrinks with it, thereby preventing the glass from being broken.

I claiu1- 1. In apparatus for the manufacture of glassware with threaded sockets, a mold having a peg projecting into the mold-cavity and a thin hollow threaded metal ferrule set removably on the peg and adapted to receive the glass around it, said peg having an end cavity for the formation of an overblow,substantially as and for the purposes described.

2. In the manufacture of glassware having a threaded socket, the improvement herein described,which consistsin placingathreaded hollow sheet-metal thin-walled ferrule in a mold, shaping the glass around the ferrule, and then removing the ferrule, substantially as and for the purposes described.

In testimony whereof I have hereunto set my hand this 27th day of August, A.D. 1890. CHARLES ULFIG.

IVitnesses:

A. G. CAMPBELL, G'Us'r. Konrrnnu. 

